Insulating and protective covers for insulating or protecting heatable plug connections are known in prior art. Plug connections provided with such an insulating and protective cover or outer encapsulation will here be referred to below as a connector assembly. They are used to connect at least two line parts or media lines, as well as to hook up a media line to any aggregate, in particular one provided in a motor vehicle. These media lines and line parts thereof are used to carry various types of media, wherein the latter in part exhibit a high freezing point, and hence already tend to freeze at relatively high ambient temperatures. As a result, the actual functions to be performed by these media can be impaired or even completely prevented. This is possible in particular in water lines for the windshield wiper system in vehicles, and primarily in so-called AdBlue® lines, wherein AdBlue® is an ultrapure reducing agent for so-called SCR catalyst systems (SCR=selective catalytic reduction). Therefore, a heating option for the media line or at least parts thereof and the plug connections is usually provided, so as to prevent the media therein from freezing or enable their thawing. In order to provide outer insulation and protect against damage, media lines and plug connections, including various transition regions between the latter and first connection regions for hooking up the media line, can exhibit insulating and protective covers.
For example, such an insulating and protective cover in the area of the plug connections of a media line is known in the form of an outer encapsulation from EP 1 985 908 A1. Providing the outer encapsulation to envelop the plug connection in an insulating manner makes it possible to include a volume of air between the latter and the outer encapsulation, which permits a thermal insulation. Such an encapsulation or insulating cover only insulates part of the distance traversed by a medium through a media line encompassing at least one plug connection. In addition, since these transition regions are not insulated, the medium can freeze or frozen locations can become difficult to thaw precisely in the transition region from the one plug connection to the other plug connection joined with the latter, wherein in particular the connector part on the one plug connection and the coupling part on the other intermesh.
In order to prevent this freezing and difficulty thawing, DE 10 2010 035 028 A1 proposes that the outer encapsulation of the plug connection be designed in such a way that both connection regions of the latter also be covered by the encapsulation, so as to thereby also insulate the second connection region, for example one used to hook up a motor vehicle aggregate, and the latter. The first connection region can be provided with a retaining element, which engages the connector part of the adjacent plug connection and retains the latter in the coupling part on which it is situated. While lengthening the insulating cover or encapsulation so as to also cover a connector part in the transition region between two insulating covers of two interconnected plug connections does basically prove advantageous, it cannot be done without a higher outlay, since the plug connections must be designed accordingly. Furthermore, this cannot automatically be done for any line configuration. For example, while the so-called overplugging region in SCR systems is comparatively large, a gap still remains between the encapsulation of two adjacent, intermeshed connecting and coupling parts of two plug connections after the spring back, through which cold can penetrate and cause the medium flowing therein to freeze. The connection between two plug connections in SCR lines or SCR line systems is established by plugging the coupling part onto the connector part or conversely the connector part into the coupling part. A retaining clamp of the coupling part here engages behind a protruding collar of an SAE connecting contour (SAE J2044) of the connector part. The coupling part is plugged onto the SAE connector part until it hits a stop, a process referred to as pushing over. The retaining clamp of the coupling part here latches behind the collar of the connector part. Pulling back the coupling part against the connector direction causes the retaining clamp to reach a locked position, in which the coupling part can no longer be detached from the connector part without releasing the retaining clamp. In order to mate, i.e., push the coupling part onto/over the SAE connector part until it hits the stop, and be able to latch the retaining clamp behind the collar of the connector part, a sufficient length must be provided for the connector part on the side remote from the coupling part behind the collar situated thereon. Since the coupling part is pulled back against the connector direction for purposes of final positioning in the locking position, a relatively large distance remains between the front side of the coupling part and a front side of a flange of the connector part or an encapsulation covering the latter. This intermediate region or transition region on the connector part is correspondingly not insulated, so that the medium flowing through the latter can become frozen in this transition region. Given multipart lines with several line parts put together in a corresponding manner, it may happen that this problem is not encountered at every junction between two line parts, but rather only partially, in particular at locations situated remotely from a heat supply, i.e., in particular remotely from an engine of a vehicle, at a location inside the vehicle or on the vehicle, which is highly exposed to the ambient temperature or airstream while a vehicle is moving or standing idle, for example when arranged under or in the vehicle floor. The necessity of performing an overplugging so as to latch the retaining clamp, i.e., to completely join the coupling part and connector part together, requires that an inexpensive and simultaneously effective insulation here be provided to prevent the medium from freezing in this transition region.